Hardy chicken breeds?

I live in a desert. Summers here reach 115 F and winters can reach 30 F at night. My family is looking for good survivor chickens because we keep loosing them to the heat, mysterious illnesses, and dogs (sometimes our own).
Mainly, they are for egg production purposes. (Family is a little squeamish about the meat idea)

What we need is,

-High egg production (preferably 5+ a week)
-Extreme heat and cold tolerant
-Foraging skills (we would like them to get most of their own food. Mostly what they eat here is weeds with the occasional insect because it's so dry and irrigation is currently out of our reach.)
-Disease resistant
-Capable of fending for itself. (knowing when to run and when to not take bull from our chasing 10 pound poodle mix)

What we've had,

Barred rocks: Most susceptible to heat breed that we've had. They only laid less than half of the number that we had. They can peck each-others butts to the point that they kill each other when they are confined.

White leghorn: The most egg productive for sure. They are so flighty that they fly over the fence into the back where the boxers make short work of them. One of them would dive under things and get herself stuck, thus she's the only one that's still alive. This same one got broody, twice, If you'd believe it.

Andalusian: Even more flighty than the leghorn. Egg production was almost as good, although not as big. They would explore until they got lost or stuck.

Red Star: Our favorite so far. They are the most friendly. Egg production is impressive (more than andalusion, less then the leghorn) They slowly died off one by one from some sort of illness.

Rhode island red: They are our newest batch (the pet club employee said they were red stars) They are over 7 months old and have yet to lay eggs. They are terrified of our single little leghorn that is half their size, including the big surprise rooster. (there were two but one was killed by the neighbor's husky.) One recently died from illness. She was very slow and weak, felt like she weighed an ounce, and had scabs all over her face and comb.

Reading your list of requirements made me think White Leghorn and reading why you say they didn't work out doesn't change the answer for me as that sounds like a problem with your containment and not with the chicken.

So you have low fences which means you need a heavy bird that can't jump them.

However you have high heat and other demands that require a small productive bird.

Quote: Here, you are asking too much of any chicken, frankly. You need to fix the dog problem here, not the chicken problem.

Quote: I can tell you it was most likely internal laying, a common ailment of high production hatchery breeds. This is the downside to high production, especially with hatchery stock's sucky genetics.

My friend Ellie has your exact climate-she's out in the Cottonwood area and has Barred Rocks, Cochins and Easter Eggers so I have some knowledge of what she has to do to manage her birds.

I've never had BRs have issues being confined, feather picking or anything of the sort and neither has Ellie that I've ever heard. They've never caused trouble here, whether hatchery stock or true heritage stock and they are excellent layers, generally. Not sure where you got yours, but I tend to think maybe you don't have enough room for your birds or they are not getting enough proper nutrition, if they are that bad.
The statement below makes me wonder if they get what they need or they'd not be picking feathers. Mine never do that because they get proper protein levels. You can't expect a hen to produce eggs and stay civil to the coop mates if they are malnourished.

Quote:That said, my Easter Eggers do well in heat and cold. I don't recall how my Wellies or my Speckled Sussex did-we don't get near as hot as you do (I'm in the mountains of n. Ga at 2000 ft). Never had Cornish.

For your environment, I'd have a bird who is not densely muscled nor tightly feathered. My Brahmas did very well in heat and cold, but they probably won't give you super high egg production-mine were very good layers until they were about 3-4 years old. I have one left who is almost 8, but she hasn't laid in awhile.

You'd need a lighter bodied breed, generally, for that purpose. Leghorns, good quality ones, should fit the bill for egg production and heat tolerance, but they can fly over your fence.

I agree with LanceTN that you may not be able to get everything you want in one bird and no chicken can truly defend itself against a dog. In fact, being constantly chased by one can stop your egg production in its tracks.

Quote: This list cannot be done. It's the ingredients for the perfect chicken, but I don't believe you can find that in any one breed. No chicken is resistant to disease, overall. Healthy chickens with strong immune systems are the only way for a chicken to resist viruses and bacteria, but no breed is truly resistant, other than the Egyptian Fayoumi comes to mind as being resistant to some diseases including Marek's. They are not good egg producers and generally a wild chicken so they fly over any fence, they do forage very well, very heat tolerant, but not sure how cold tolerant.

My point is you cannot get everything on your list in one chicken. My best producing chicken of all time was a Barred Plymouth Rock, six to seven eggs per week for her first three years, then five to six her last year. Even during molt, she quit laying for two weeks, then started back up. Other than that, my absolute best producers are usually mixed breeds. My best producer now is a BLRW x Blue Ameraucana hen who is going on 5 years old. She matches every one of your points, except maybe fending for herself against a dog (wouldn't expect that of any chicken)but that is just her.

I second Speckledhen's response entirely. You might want to re-evaluate your environment to create a more "chicken-friendly" situation, thereby eliminating the one factor of which you have some control. Safety while free-ranging, and, ample space in confinement. Appropriate numbers of birds for the space you have set aside. Eliminate the stress created by dogs (separate areas, etc). Feeding a balanced diet to supplement any nutrition limitations of foraging alone. Climate is the factor you can't control, but you can help reduce the effects of its extremes with ample shade, water, shelter from the elements. My Black Australorps have done well now for 4 years in the extremes of high heat and humidity and sub-freezing night temperatures, but I make every attempt to provide the best conditions possible for them.

You bring up excellent points. Honestly, I knew these expectations were really unrealistic. (my mom was suggesting things I should add, including the dog bit). I want you to know that we take good care of them, as much as we can that is. We currently have seven chickens in a coop that is 15x15 and 15ft tall with lots of roosting perches. They always have plenty of feed and water (they just eat a lot so we are hoping to change that). Most of the time they are kept in the coop because of our dog. When we let them out the dog is kenneled. The only reason he had the opportunity was because the 10 year old didn't realize what she was doing and let them out together.

We live on a half acre of land that is boarded by a 5 Ft fence. The time the neighbor's dog got the rooster was a couple days after our record setting "wettest day ever" and the ft and a half tall flood swept the dirt under the fence making us unable to contain the boxers in the back. Since they always run loose when they get the chance, we had to contain them in the only structure that lasted, the chicken coop (We switched them. We didn't just throw them in with the chickens). Dad hates the idea of animals indoors. He's kind of OCD about that. Just trust me when I say we can't just make him get over it.

Anyway, the chickens were completely unprotected for about a week and jumping a 5 Ft fence is no small feat for a husky. Our neighbors have done better containing him since.

The barred rocks did terribly with laying in the summer, almost all of them layed every day in the winter. Not sure why they were so mean to each other otherwise. They had a plenty big coop. They all were killed one night. We don't know what happened. The coop was left and found closed and there aren't any holes larger than a ping pong. The hens were missing except one was left dead in the coop. The barred rock rooster was found dead in the back behind the fence. We know the dogs didn't touch him because he was physically intact except for a quarter wide hole in his chest, like someone ran him through with a spear.

We had two red stars at the time. One was acting like she had internal damage and eventually died a couple weeks later. The other showed no unusual signs and surprised all of us when we found her dead just before the flood (perhaps internal laying? She hadn't been laying any eggs since the traumatic experience. That was a full five months).

Kids siphoning your gas at night and stealing things is common here. Plus we live a block north of an indian reservation. That's our only suspect.

I remember looking into that Egyptian breed. Too bad it's so wild and only lays two eggs a week, huh?

There's not much we can do about the environment for the leghorns. Extend the really long fence? Good luck convincing dad to.